Regulation of direct current



July 29. 1952 G. VILLEBONNET ,5

REGULATION OF DIRECT CURRENT SOURCES FOR THE SUPPLY OF ELECTRIC RECEIVERS Original Filed Feb. 14, 1948 2 SHEETSSHEET 1 a INWENTOTL vwezbowvyQj/i WM" 5 ,VW

y 29, 1952 G. VILLEBONNET 3 REGULATION OF DIRECT CURRENT SUURCES FOR THE SUPPLY OF ELECTRIC RECEIVERS Original Filed Feb. 14, 1948 2 sxmms-sm'r 2 INVENTOR -GEORGE5 VILLEBONNET A BY 721m, a aha/QM g4 ATTORNEYS Reissued July 29, 1952 REGULATION OF DIRECT CURRENT SOURCES FOR THE SUPPLY OF ELECTRIC RECEIVERS Georges Villebonnet, Gentilly, France Original No. 2,588,748, dated February 19, 1952,

Serial No. 8,378, February 14, 1948.

Application for reissue May 5, 1952, Serial No. 286,047. In France November 24, 1942 Matter enclosed in heavy brackets I: 1 appears in the original patent but forms no part of this reissue specification; matter printed in italics indicates the additions made by reissue.

4 Claims.

The present invention relates to new and useful apparatus for regulating the voltage supplied to electrically operated apparatus requiring'substantially constant voltage, such as telecommunications for example, and which relies on sources of direct current.

In such installations, and particularly telecommunication systems, a usual source of current is from lead or cadmium-nickel accumulators or secondary batteries, and, as is well known, the voltage thereof is variable, whether the batteries are arranged in series, in parallel, and in buffer relationship or in trickle charge output. In such systems the voltage supply must be relatively constant, a tolerance plus or minus of only two volts being quite usual. Such voltage variations may be due to the loading conditions of the system or to variations in the voltage output of a particular cell in the source of supply, and are according to one known method corrected by addition or removal of further cells to the battery. According to another known method a commutator is employed to introduce resistance elements, for instance, in series with the battery to reduce the voltage. Alternatively elements having a counterelectromotive force, and operating as electrolytic resistances may be so inserted or removed. Such resistance or counter E. M. F. elements have many disadvantages. They are quite cumbersome; they give ofl. gases resulting from electrolysis and require the same electric canalizations and the same care as the normal batteries in the circuit. Moreover, the switching elements for their insertion and removal have to be designed to take into account the presence of residual energy in the switching circuit.

It is the object of the present invention to provide a new and useful method and apparatus for accomplishing the desired voltage regulation in an installation of the type referred to in a simple manner and with great advantages over the prior art as hereinafter brought out.

The accompanying drawings forming part of this specification illustrate the present invention and the manner of its operation.

In the drawings:

Figure 1 is a schematic diagram of a voltage regulator for a direct-current power supply according to the invention employing manual control;

Figure 2 is a diagram of a modified regulator according to the invention, also using manual control; and

Figure 3 is a schematic diagram of a regulated battery-fed power supply according to the v invention.

According to the present invention there are employed as resistance elements for effecting a desired voltage drop in series with the battery whose output voltage is to be stabilized a plurality of dry rectifier cells of known types such as go upon other features such as the nature of the rectifier cell and the ambient temperature. In certain cases, the combined action of these various factors make it possible, as is well known, to provide a dry contact cell, the voltage drop of which is practically constant when the cell is traversed in its preferred direction or direction of greater conductivity by a variable direct current. Theconnection of several such cells in series, in parallel, or in mixed grouping, permits providing a dry resistance element unit having the same useful electrical characteristics as the previously used resistance elements mentioned hiereabo've, with none of their disadvantages.

By connecting a group of such rectifier cells of selected characteristics in series with the source of direct current to be regulated, each cell being capable of causing a small voltage drop, such as several tenths of a volt, and by utilizing a number'ofcells which together can equal the voltage variation tolerance for the specific installation, a voltage regulator is provided having the characteristics of, firstly, progressive regulation, since the voltage drop in each cell element may well be of the order of a few tenths of 9. volt or more, and secondly, a great simplicity of the arrangement since the absence of residual energy permits the use of simple well known switches or commutators without any intermediate resistances being re-' quired.

as,ss1

For the same reason, it is possible to proceed directly to insert the cells into the circuit or to short-circuit them therefrom. The switches and relays. etc. which can be used for this purpose present a high factor of safety and maybe provided with simple and well known con tacts.

A third advantage of the invention is to reduce the ,bulk of the regulators required. By way of example, a dry rectifier unit comprising a group of magnesium-copper sulphide cells connected to a storage battery of 100 ampere-hour capacity at 2i volts requires a volume of less than a centimeter cube.

Fourthly, no upkeep or maintenance is required since dry contact cells require no upkeep whatsoever and the use of such cells in the circuits of the invention has no influence on their usual length of life.

Referring now to the drawings, in the diagram illustrated in Fig. 1. a and b' are the two input terminals of a source of direct current with variable voltage which may be a bank of batteries, while c and d are the two output terminals to which it is desired to apply a practically constant voltage, and which are connected to the terminals a and b by wires e, f.

Inserted in the wire e there is provided a dry rectifier cell unit made up of a group of dry cells g which in this exampl are in series connection. The cells g are connected. as shown, to the contacts or a commutator having a switch arm n, and

the last cell is connected to the wire e. It will be connected actively into the circuit will not be short circuited. Again. however, any desired number of cells g may be placed in the circuit at will.

Fig. 3 illustrates voltage regulation by means of dry rectifier cells according to the invention in an automatically regulated power supply. In this embodiment of the invention. regulation of the voltage of a set of batteries shown as battery 4 is eifected by automatically inserting one, two or three dry-contact cells I, 2, I, these being equivalent to cells s (Fig. 1). This insertion of one of said cells is eilected by opening a contact and its removal is effected by short-circuitingit. The contact being opened, the cell involved will be connected in series with the battery I. The positive output terminal c or the regulated supply is connected through line I with the entrance end of the voltage dr ppin unit comprising dry rectifier cells I, 2. I. poled to carry the current or battery 4 in their direction of greater conductivity. The exit end of this unit is connected through line Ill, line llLpositivc input terminal a and line "I to the positive terminal of battery 4. The negative terminal of the battery is connected to regulator input terminal b and thence via'line Ill to regulator output terminal d.

- Automatic operation to insert or remove cells i, I or 3 from the circuit in accordance with the voltage across the load terminals c. d is ensured sociated resistances and I in parallel across the terminals 0, d whereby they will be fed with the corrected or regulated voltage. 'To this end, supply terminal c is connected through wire I to junction 9 terminal while the other supply terminal b is connected to the Junction in through 'wire I". The coils 0r windings of both relays l and I are connected, in series with variable resistors i and I, between junctions I and I".

In contradistinction thereto. relays III, II, II,

these variations into impulses directed by the switching relay It to the short circuiting relays II. II and I: which control the short-circuiting and reinsertion of the cells I. 2 and 3:

Relay 8 is of the minimum threshold type, i. c. it will de-energize when the voltage applied to. its winding falls below a specified minimum. The threshold value thereof, in terms of supply voltage at c, d may be adjusted by the rheostat I connected in series with the coil of relay 8. When relay I becomes de-energized upon decline of the supply voltage below the minimum set at rheostat 6, relay I relaxes its armature. allowing'its normally closed contacts I and 82 to close. when I: closes, rheostat i is short-circuited,-the current through the winding is increased and the relay attracts its armature again, reopening contacts II and II. If during the de-energization" of relay I the supply voltage has not risen above the lower level of the regulated voltage range set at rheostat 8, relay l will immediately de-energize again, allowing its contacts to close. At each closing of contact II, a negative impulse is sent via line is to contact blade ill of switching relay il. Thus relay 0 will continue to "beat," i. e'. to open and close, until the minimum supply voltage is reached at terminals c, d.

Relay 8 is of the maximum threshold type, i. e. it will energize when the voltage applied to its winding increases above the specified maximum. The upper limit of regulated supply voltage at c, d corresponding to this maximum may be adjusted by means of rheostat I. When the supply voltage rises above the maximum so set. relay 8 will be energized. attracting its armature and closing its normally open contacts II and If.

by means of a six-relay system comprising relays I, I. ll, II, II and II, all adaptedto be energized Upon closing of Ii. the relay winding is shortcircuited. and the contacts reopen. At each closin 9i sends a negative impulse via line ii to switch blade III of switching relay It. If upon reopening its contacts. relay. I again experiences a voltage above its threshold, it will close its contacts once more. and so on. until the supply voltage falls to a value within the range of regulation.

The switching relay ill is provided with two contact blades iii and Ill each having two contacts. Illa. lfllb, and Ilia, lllb, respectively. Contact blade llll is adapted to transmit from connecting wire ii the control impulses resulting from the operation of relay I. Contact as,ss1

when an even number of short-circuiting relays are energized (I. e., none or the first two) and it will remain in its deenergized condition if an odd number of short circuiting relays are energized (l. e.. the first or all three of them). ergizing winding of relay II is mounted in series with contact blade III of relay II (via normally closed contact Illa). with blade III of relay II and with blade III of relay II (via blade III). Relay III is therefore de-energized if relay II only is energized (contact I Ila being open) or ii relays II, II and II are simultaneously energized (contact III being opened). Similarly relay II is energized if relays II, II and II are de-energized (I IIa being closed) or if II and II are energized (III, IIIa and lb being closed).

Relay III is o! the slow-acting type due to the presence of a condenser II connected across its energizing winding. Thus, when a change in supply voltage is created by inserting an element I. I or I or by short-circuiting one of them. this is accompanied, in fact is caused by, a corresponding change in the number of energized short-circuiting relays. However, due to the aforesaid condenser II, the alteration in position of relay II resulting therefrom will take place only after a time lag during which additional negative pulses from relays I and I are inoperative.

Each of the relays II, II and II is provided to close or open a short-circuiting contact II I, III or III in the chain of dry rectifier cells I, I or I. These relays are connected in cascade so that I no one of them can be energized unless the preceding relay is already energized. To this end. the winding of relay II is connected via a resistor II and line [II] 25 to the positive terminal The en-' of the battery I while the winding of relay II is a connected thereto through resistor II by means of normally open contact I IIb and [plate] blade III of relay II. The winding of relay II Is connected to the positive terminal of the battery through resistor II via normally open contacts [24b and IIIa of relay II and lb of relay I. I. Similarly, none of the relays II, II and II can be brought into its de-energized position so long as any of the following is still energized. Moreover. the relay I I will provide to short-circuit the first cell I while the relay II will short-circuit two cells I and I and the relay [I] 13 will shortcircuit three cells I, I and I. This result is achieved in a very simple manner. Positive terminal c of the power supply is connected to each relay by wires III, I and III. Junctions I, I and I in the series connection of rectifier cells are respectively connected through wires III, III and II to the contacts III. III and III. when, for instance, the relay II is set to operate. contact III will short-circuit simultaneously the cells I and I through the medium of wires III and III. Similarly, contact III of relay II will short-circuit the three elements I, I and I while the contact III will only short-circuit the element I.

For a clearer understanding or the manner in which the apparatus according to this invention operates. it is helpful to consider a particular case. The selected example may be as follows: the voltage becomes lower than a predetermined lower limit while all three elements I, I and I are actually in operation in the circuit.

With all of the cells I, I and I in the circuit,

6 age below the lower limit of the regulated range) and its contacts II and II are open. On the other hand relay I- is tie-energized, and its contacts II and II are also open.

Initially also. the three cells I, I and I bein in the circuit, the contacts III. III and III are open and the three relays II, II and II are deenergized. Therefore, the switching relay II is energized, and its contact III is in position to connect wires II and II.

Under the conditions assumed, if the supply voltage at c, d becomes lower than the preselected value, it is necessary to short-circuit from the circuit one or more of the elements I. I and I. when the supply voltage fals below the preselected value, relay I tie-energizes, and its contacts II and I: thus close. The negative supply terminal d connected by wires III and II with contact II is then connected with the positive terminal a of the battery through wires II. II

(since. with all of relays II, II and II de-energized, switching relay II is energized to connect switch blades III and III with normally open contacts lb and IIIb. respectively), normally .closed energizing contact III, wire III. winding of relay I I. wire I", resistor II. and wire II. This will energize relay II, closing its normally open holding contact III and opening its energizing contact III. Instead of being energized through contact III relay II will then be energized through contact III and wires II and III to the negative terminal of the battery, connection to the positive battery terminal being via wire I", resistor [III] 21 andwire II as before.

As the winding of relay II is now permanently energized regardless of negative pulses from wire II. it will hold contact III closed, and the cell I will be short-circuited.

Short circuiting of cell I will produce an increase of the supply voltage at c, d. 11 with this increase the voltage at c, d returns to a value between the predetermined upper and lower limits, relay I will return to a steady energized condition with its contacts open. Relay [II] 9 of course will remain tie-energized with its contacts open.

If in spite of the short circuiting of a cell, the supply voltage at c, d remains below the permissible minimum. the next impulse from contact II (occurring upon recloslng' of contact II when relay I again relaxes its armature due to insufficient energizing voltage) will be directed toward relay II via wire I'I, since relay II relaxes its armature upon energization of relay II. With contact blade III closed at normally open contact III!) by the prior energization of relay II, relay II is permitted to be energized, shorting out rectifier cell I. Relay [II] 10 is then reenergized so that the next negative pulse from contact II will energize relay II, again via wire II.

When the power supply voltage at the output terminals c and d changes in the reverse direction, i. e. rises above the upper limit of the regulated range. and with relay II only assumed to have been energized, for example, the operation is as follows: upon increase of the voltage at c. d above the maximum. relay I will be energized. and its contacts II and II -will close. The negative supply terminal d is then connected to junction III and thence via closed contact II. wire II. contacts III. "In. wire II and contacts III. IIIb to wire I" and the winding of relay II. At the same time the other end of the winding of relay II is connected to the negative supply voltage through contact ill and wires Ill and H.

Due to the presence or resistor Ii, thepositive voltage on wire 2| is isolated, and the winding oi relay ii is short-circuited. Normally open contact ill thereupon opens. The de-energization o! relays II and I3 is similarly. efiected with the ductivity a current torced'through them by the.

battery. andlmeans responsive to the voltage the series connection of batteryand rectifiers to short-circuit said rectifiers successively as said voltage falls below a minimum value and to, reinsertl said rectifiers successivelyinseries with the battery as said voltage rises above a maximum-value.

2. A regulated direct current power supply comprising'a battery, a plurality of drycontact rectifying elements connected in series with the battery and poled to pass in their direction of low resistance, a current forced-through them by the battery upon completion or a circuit includ ing the battery and rectifying elements,- a plu rality oi shortclrcuiting relays, one breach of said elements, a normally open contact on each of said relays connected to short-circuit when closed one of said elements, a minimum and a maximum voltage relay each having its winding connected in series with a resistance across thc combination oi battery and rectifying elements in series. and a switching relay controlled by the state of energization of the short-circuiting re-i lays to direct energizing pulses from the minism'um voltage relay and de-energizins pulses from the maximum voltage relay to the windings'di the short-circuiting relays in a specified order.

3. A voltage regulator for a source direct current voltage comprising a pair or inputterminals for connection to said source, a pair'oi output terminals for connection to a load, a plurality of dry contact rectifying elements conj nected in series between one of said inputand one or said output terminals and poled to pass in'their direction of low resistance a current forced through them by the source upon conspletion of a circuit'including thesource and rot;- tiiying elements, a plurality oi short-circuiting relays. one for each of said elements;v a normally open contact on each of said relays connected to short-circuit when closed one or said elementssa minimum and a maximum voltage relay eaoh having its winding connected in series with 'a resistance across said output terminals. afirst normally-closed contact on said minimum voltage relay connected to short-circuit when closed the resistance in series with its winding, a second normally closed contact on said relay connecting when closed one at said inputterminals to a first contact blade at a switching relay, a

that normally open contact on said maximumv to a second blade of said switchingrelay. a switching relay having its winding connected across said input terminals via a normally closed switch relaycontrolling contaeton a first one 0! the short-circuiting relays and also via a noranally closed switch relay controlling contact on two normally open switch relay controlling contacts on the second short-circuiting relay and a normally open switch relay controlling contact on the first short-circuiting relay, a normally closedenergizing and-=a normally open holding contact on each of the short-circuiting relays connecting with their respective windings, a normally open and a normally closed short-circuiting relay energizing contact on the switching relay associatedwith said first contact blade connecting the second normally closed contact on the minimum voltage relay to the energildng contacts oi the short-circuiting relays in a specified order and a normally open and a normally closed de-energizing contact on the switching relay associated with the second contact blade thereof connecting the second normally open contact 0! the maximum voltage relay to the ends o! the short-circuiting relay windings opposite their energizing contacts in the reverse order.

4. A voltage regulator for a source or direct current voltagescomprising a pair of input terminals for connection to said source,- a pair of output terminals for connection to a load, a plurality 01' dry contact rectifying elements connected in series between one of said input and one of said output terminals and poled to pass in their direction of low resistance a current iorced through them by the source upon completion of a circuit including the source and rectiiying elements, a plurality of short-circuiting relays, one for each of said elements, a normally open contact on each 01 said relays connected to short-circuit when closed one of said elements. a minimum and a maximum voltage relay each having its winding connected in series with a resistance across said output terminals, a first normally closed contact on said minimum voltage relay connected to short-circuit when closed the resistance in series with its winding, a second normally closed contact on said minimum voltage relay connecting when closed one of said input terminals to a first contact blade oi a switching relay. a first normally open contact on said maximum voltage relay connected toshort-circuit when closed the winding of its relay, a second normally open contact on said maximum voltage relay connecting when closed the same input terminal to a second blade of said switching relay. a switching relay having its winding connected across said input terminals via a normally closed switch relay controlling contact on a first one or the short-circuiting relays and also via a normally closed switch relay controlling contact on a third of the shortcircuiting relays and one of two normally open switch relay controlling contacts on the second short-circuitlng relay and a normally open switch relay controlling contact on the first short-circuiting relay, a normally closed energizing and a normally open holding contact on each of the short-circuiting relays connecting with their respective windings, a connection from a normally open contact of the switching relay associated with its first contact blade to the energizing contacts oi the first and third short-ch'cuiting relays, a connection from a normally closed contact associated with the first contact blade of the switching relay to the energizing contact 01" the second short-circuiting relay. a connection from a normally open contact associated with the second contact blade of the switching relay to the end of the winding oi the second short-circuiting relay remote from its energizing contact a third 0! the short-circuiting relays and one of and to the normally open switch relay control- 9 ling contact on the first short-circuiting relay and to one 01' the normally open switch relay controlling contacts on the second short-circuiting relay, a connection from a normally closed contact associated with the second blade 01 the switching relay leading via a further normally closed contact on the second short-circuiting relay to the end of the winding of the first shortcircuiting relay remote irom its energizing contact and via a further normally open contact on the second short-circuiting relay to the corre spending end of the winding oi the third shortcircuiting relay and to the second normally open switch relay controlling contact on the second short-circuiting relay.

- GEORGES VIILEBONNET.

REFERENCES CITED The following references are of record in the ille of this patent or the original patent:

Number 15 Number 427.430

10 UNITED STATES PATENTS Name Date White Sept. 6, 1910 Tatum June 13, 1916 Conway Dec. 19, 1922 Shackleton Sept. 7, 1926 Roberts Dec. 25, 1929 Niles et a1. Dec. 31, 1929 Brooks Sept. 22, 1931 Robinson Dec. 29, 1931 Devol Oct. 18, 1932 Timmons May 8. 1934 FOREIGN PATENTS Country Date Great Britain Apr. 24 1935 

